Slip Systems in Manganese Zinc Ferrite Crystals

Abstract

As-received and annealed manganese zinc ferrite crystals were deformed in uniaxial compression along <100>, <110> and <111> compression axes at 1100°C. The compositions of the two types of crystals were calculated to be Mn ²⁺_0.536 Zn ²⁺_0.326 Fe ²⁺_0.077 Fe ³⁺_0.040 □_0.020 0₄ and Mn ²⁺_0.538 Zn ²⁺_0.327 Fe ²⁺_0.099 Fe ³⁺_2.024 □_0.01190₄ based on the Fe²⁺ content and assuming that the Mn is all in the 2+ state. At 1100°C the easy slip system is {111}<110> as determined by slip trace analysis on the crystals compressed along <110> and <111>. This behavior differs from nonstoichiometric magnesium aluminate spinels where {110}<110> slip dominates. From these tests, the lower cation defect concentration, annealed specimens are softer at yield than the as-received, higher cation defect concentration specimens, again differing in behavior from the aluminate spinels which have a much larger range of defect concentrations. TEM examination of deformed specimens revealed a 3-D network of dislocations as a consequence of easy climb under these conditions.